U.S. patent number 6,883,832 [Application Number 10/352,016] was granted by the patent office on 2005-04-26 for gas bag for a vehicle occupant restraint system and a gas bag module.
This patent grant is currently assigned to TRW Automotive Safety Systems GmbH. Invention is credited to Markus Keutz.
United States Patent |
6,883,832 |
Keutz |
April 26, 2005 |
Gas bag for a vehicle occupant restraint system and a gas bag
module
Abstract
A gas bag for a vehicle occupant restraint system comprises a
gas bag wall, which in the unfolded state of the gas bag (22)
delimits an indentation (30) with an orifice (28) or an opening,
and a closure piece (40) fastened to the gas bag wall, which in the
inflated state moves in front of the orifice (28:) of the
indentation or in front of the opening and covers it. The closure
piece (40) is formed from at least two covering pieces, arranged
one over the other, overlapping each other, which respectively have
a margin section which is not fastened to the gas bag wall.
Inventors: |
Keutz; Markus (Rossdorf,
DE) |
Assignee: |
TRW Automotive Safety Systems
GmbH (Ashcaffenburg, DE)
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Family
ID: |
27614526 |
Appl.
No.: |
10/352,016 |
Filed: |
January 27, 2003 |
Foreign Application Priority Data
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Jan 30, 2002 [EP] |
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02001901 |
Dec 3, 2002 [DE] |
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202 18 732 U |
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Current U.S.
Class: |
280/743.2;
280/729; 280/731; 280/743.1 |
Current CPC
Class: |
B60R
21/203 (20130101); B60R 21/231 (20130101); B60R
21/217 (20130101); B60R 2021/161 (20130101); B60R
2021/21525 (20130101) |
Current International
Class: |
B60R
21/20 (20060101); B60R 21/16 (20060101); B60R
002/16 () |
Field of
Search: |
;280/743.2,743.1,731,729 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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38 33 889 |
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Apr 1990 |
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DE |
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20102115 |
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Aug 2001 |
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DE |
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20022018 |
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Dec 2001 |
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DE |
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Other References
US. Appl. No. 10/036,233, filed Dec. 26, 2001 entitled "Gas Bag
Restrain Device". .
U.S. Appl. No. 10/068,379, filed Feb. 6, 2002 entitled "Gas Bag
Module"..
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Primary Examiner: Ilan; Ruth
Attorney, Agent or Firm: Tarolli, Sundheim, Covell &
Tummidno L.L.P.
Claims
What is claimed is:
1. A gas bag for a vehicle occupant restraint system, with a gas
bag wall, which in the unfolded state of the gas bag (22) delimits
an indentation (30) with an orifice (28) or an opening, and a
closure piece (40) fastened to the gas bag wall, which in the
inflated state moves in front of the orifice (28) of the
indentation or in front of the opening and covers it, characterized
in that the closure piece (40) is formed from at least two covering
pieces, arranged one over the other, overlapping each other, which
respectively have a margin section which is not fastened to the gas
bag wall.
2. A gas bag according to claim 1, characterized in that the
non-fastened margin sections are arranged so as to be staggered
with respect to each other.
3. The gas bag according to claim 1, characterized in that the
covering pieces are fabric pieces (42, 44) which are sewn on to the
gas bag wall.
4. The gas bag according to claim 3, characterized in that the
fabric pieces (42, 44) are arranged so as to be slightly staggered
with respect to each other and are fastened to the gas bag wall on
their outer edges by means of an encircling seam (46) which does
not take up all the margin sections of each individual fabric piece
(42, 44).
5. The gas bag according claim 1, characterized in that the
covering pieces are rectangular and the margin section of the one
covering piece which is not fastened to the gas bag wall is opposed
to the margin section of the other covering piece which is not
fastened to the gas bag wall.
Description
TECHNICAL FIELD
The invention relates to a gas bag for a vehicle occupant restraint
system with a gas bag wall, which in the unfolded state of the gas
bag delimits an indentation with an orifice or an opening, and with
a closure piece fastened to the gas bag wall, which in the inflated
state of the gas bag moves in front of the orifice of the
indentation or in front of the opening and covers it. The invention
further relates to a gas bag module with a gas bag according to the
invention.
BACKGROUND OF THE INVENTION
From the EP-A-1 231 116 a gas bag of the type initially mentioned
is known, which has a ring-shaped chamber which is to be inflated,
which surrounds an indentation. The indentation extends from the
front wall of the gas bag, facing the vehicle occupant, centrally
towards the rear. The deepest point of the indentation is formed by
a fabric piece which is fastened permanently to the gas bag module
and therefore is not moved towards the occupant during unfolding.
In the inflated state of the gas bag, the closure piece, which is
fastened to the gas bag wall, covers the opening of the
indentation, so that the vehicle occupant is prevented from
penetrating into the indentation.
BRIEF SUMMARY OF THE INVENTION
The invention provides a gas bag with a closure piece which ensures
a complete and secure covering of an indentation or of an opening
of the gas bag, the gas bag making possible an optimized material
distribution in the folded state and a symmetrical opening
behaviour during unfolding.
This is achieved in a gas bag of the type initially mentioned in
that the closure piece is formed from at least two covering pieces,
arranged one over the other, overlapping each other over a large
area, which respectively have a margin section which is not
fastened to the gas bag wall. Through the provision of at least two
covering pieces, a non-symmetrical placing of a one-part closure
piece around a central holding piece of the gas bag module or the
like, necessitated by the construction, is avoided. In the gas bag
according to the invention, such a holding piece can extend through
the closure piece, owing to the open margin sections, so that a
symmetrical arrangement of the closure piece around the holding
piece is possible. The stressing of the covering piece and of the
section of the gas bag wall connected therewith is reduced compared
with a single-layer closure piece, and the opening behaviour is not
influenced, as with a single-layer closure piece which is fastened
non-symmetrically. With the closure piece according to the
invention, in addition to an indentation which is delimited by the
gas bag wall, a gas outlet opening formed in the gas bag wall can
also be covered.
The preferred embodiment of the invention makes provision that the
non-fastened margin sections are arranged staggered with respect to
each other. Fabric pieces sewn on to the gas bag wall are suitable
as covering pieces.
A particularly simple and favorably priced manufacture is made
possible in that the fabric pieces are arranged slightly staggered
with respect to each other and are fastened to the gas bag wall on
their outer edges by means of an encircling seam which does not
take up all the margin sections of each individual fabric piece.
Through the staggered arrangement of the fabric pieces, a single
encircling seam is sufficient to fasten the fabric pieces to the
gas bag wall and at the same time to form the open margin sections,
through which a holding piece or the like can extend. Therefore,
the sewing work for the closure piece is reduced to a minimum.
Preferably, the covering pieces are rectangular and the margin
section of one covering piece, not fastened to the gas bag wall, is
opposed to the margin section of the other fabric piece which is
not fastened to the gas bag wall. The covering pieces may, however,
also have the form of a triangle or of a half moon.
The invention also provides a gas bag module with a gas bag in
which the gas bag wall has a front and a rear wall section, an
indentation running in the direction of the wall section on the
rear side from the front wall section in the inflated state, which
is formed in that a part of the gas bag wall is prevented from an
unimpeded movement towards the outside of the module during the
unfolding of the gas bag. With such a gas bag module, excellent
restraint values are achieved by the gas bag according to the
invention.
According to the preferred embodiment, a centrally arranged holding
piece is provided in the gas bag module, which delimits a
ring-shaped chamber to accommodate the folded gas bag on the inner
side and which in the folded state of the gas bag extends inside
the indentation, the margin sections not fastened to the gas bag
wall surrounding the holding piece in the folded state of the gas
bag, so that the holding piece extends through the closure piece.
The holding piece generally serves to prevent a central part of a
covering of the module from moving outwards. In the folded state of
the gas bag, the holding piece extends inside the indentation, with
the indentation moving along the holding piece on unfolding and
leaving the module via a ring-shaped outlet opening.
Further features and advantages of the invention will be apparent
from the following description of a preferred embodiment and from
the following drawings, to which reference is made. In the
drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a longitudinal sectional view through a gas bag module
according to the invention with a fully inflated gas bag according
to the invention; and
FIG. 2 shows a top view onto the front wall section of the gas bag
of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a gas bag module is illustrated, which can be housed in
the steering wheel of a vehicle. The gas bag module has a mounting
housing 10 which is closed on the front side by a covering 12. In
the module, a gas generator 14 is housed, which is surrounded by a
diffusor 16. Projecting from the end face of the diffusor 16 is a
holding piece 18 in the form of a tube on which a central piece 20
of the one-piece covering 12 is fastened, so that the latter is
prevented from swiveling outwards on opening of the covering
12.
A gas bag 22 housed in the mounting housing 10 of the module has a
gas bag wall which surrounds a front wall section 24, facing the
occupant in the inflated state, and a rear wall section 26. The
front wall section 24 has a central opening which forms an orifice
28 of an indentation 30. The indentation 30 is produced in that a
part of the gas bag wall, namely the actual centre of the front
wall section, is prevented by the holding piece 18 and the central
piece 20 from a movement in the direction of the occupant. Through
the indentation 30, which is not filled with gas, a ring-shaped
chamber 32 is produced, which is to be filled with gas.
In the folded state, the gas bag 22 is housed in the module in an
annular space which is delimited radially on the inner side by the
cage 16 and the holding piece 18 and also on the outer side by the
peripheral wall 38 of the module housing 10. Reference 34
designates the sections of the covering 12 which detach themselves
from the central piece 20 on unfolding of the gas bag 22 and swivel
outwards to free an annular outlet opening 36.
So that the occupant who strikes onto the wall section 24 can not
penetrate into the indentation 30, the gas bag 22 has a closure
piece 40 which is arranged so that it moves in the inflated state,
as illustrated, in front of the orifice 28 of the indentation 30
and closes it. The closure piece 40 consists of two rectangular
covering pieces, lying one over the other, which are constructed as
fabric pieces 42 and 44 and have an identical shape. The fabric
pieces 42 and 44 are arranged so as to be staggered slightly with
respect to each other, so that they overlap each other completely,
with the exception of two opposed marginal regions 42a and 44a. The
closure piece 40 is fastened to the front wall section 24 of the
gas bag 22 by means of an encircling seam 46, the seam 46 only
taking up one fabric piece 44 or respectively 42 on the sides of
the non-overlapping margin sections 42a and 44a respectively, and
taking up both fabric pieces 42 and 44 on the other two sides of
the closure piece (see FIGS. 1 and 2). Therefore, each fabric piece
42, 44 has a non-sewn (open) side, which is opposed to the open
side of the other fabric piece.
On installation of the gas bag 22 into the module, the two open
sides of the closure piece 40 are placed around the holding piece
18, so that in the folded state of the gas bag 22, the holding
piece extends through the closure piece 40. On unfolding of the gas
bag 22, the open sides of the closure piece 40 move along the
holding piece 18 and the central piece 20 and then leave these.
Then the fabric pieces 42, 44 move over the orifice 28 of the
indentation 30 and close this completely.
The overlapping region of the two fabric pieces 42, 44, which can
be indicated in the embodiment described above by the measurement A
(see FIG. 2), is dimensioned as a function of the size of the
orifice lying therebeneath, which is to be covered, so as to be so
great that a penetration of the vehicle occupant into the
indentation 30 is avoided.
Instead of fabric pieces 42, 44 cut in a rectangular shape,
differently shaped fabric pieces (e.g. triangular or
half-moon-shaped) with opposed open sides can also be used for the
closure piece 40, which can be placed around the holding piece 18.
The term "opposed" in this case is to be understood to mean that
two identical sides of fabric pieces, lying one over the other, are
not open. It is also possible to provide a closure piece 40 with
more than two layers, whereby the positive symmetry characteristics
of the covering design according to the invention can be further
improved.
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